php开发留言板的CRUD(增，删，改，查)操作

create database form; 

use form; 

CREATE TABLE `message` ( 
`id` tinyint(1) NOT NULL auto_increment, 
`user` varchar(25) NOT NULL, 
`title` varchar(50) NOT NULL, 
`content` tinytext NOT NULL, 
`lastdate` date NOT NULL, 
PRIMARY KEY (`id`) 
) ENGINE=InnoDB DEFAULT CHARSET=gbk AUTO_INCREMENT=1 ; 

<?php 
$conn = @ mysql_connect("localhost", "root", "") or die("数据库链接错误"); 
mysql_select_db("form", $conn); 
mysql_query("set names 'gbk'"); 
?> 

<?php 
include 'conn.php'; 
if($_POST['submit']){ 
$sql="INSERT INTO message(id,user,title,content,lastdate) VALUES (NULL, '$_POST[user]', '$_POST[title]', '$_POST[content]', now())"; 
mysql_query($sql); 

//页面跳转，实现方式为javascript 
$url = "list.php"; 
echo "<script language='javascript' type='text/javascript'>"; 
echo "window.location.href='$url'"; 
echo "</script>"; 
} 
?> 
<script type="text/javascript"> 
function checkPost(){ 

if(addForm.user.value==""){ 
alert("请输入用户名"); 
addForm.user.focus(); 
return false; 
} 
if(addForm.title.value.length<5){ 
alert("标题不能少于5个字符"); 
addForm.title.focus(); 
return false; 
} 
} 
</script> 
<FORM name="addForm" METHOD="POST" ACTION="add.php" onsubmit="return checkPost();"> 
用户：<INPUT TYPE="text" NAME="user" /><br /> 
标题：<INPUT TYPE="text" NAME="title" /><br /> 
内容：<TEXTAREA NAME="content" ROWS="8" COLS="30"></TEXTAREA><br /> 
<INPUT TYPE="submit" name="submit" value="add" /></FORM> 

<?php 
include 'conn.php'; 
?> 
<?php 
echo "<div align='center'><a href='add.php'>继续添加</a></div>"; 
?> 
<table width=500 border="0" align="center" cellpadding="5" cellspacing="1" bgcolor="#add3ef"> 
<?php 
$sql="select * from message order by id"; 
$query=mysql_query($sql); 
while ($row=mysql_fetch_array($query)){ 
?> 

<tr bgcolor="#eff3ff"> 
<td>标题：<font color="red"><?=$row[title]?></font> 用户：<font color="red"><?=$row[user] ?></font><div align="right"><a href="preEdit.php?id=<?=$row[id]?>">编辑</a>  |  <a href="delete.php?id=<?=$row[id]?>">删除</a></div></td> 
</tr> 
<tr bgColor="#ffffff"> 
<td>内容：<?=$row[content]?></td> 
</tr> 
<tr bgColor="#ffffff"> 
<td><div align="right">发表日期：<?=$row[lastdate]?></div></td> 
</tr> 
<?php }?> 
</table> 

<?php 
include 'conn.php'; 
$id = $_GET['id']; 
$query="delete from message where id=".$id; 
mysql_query($query); 
?> 
<?php 
//页面跳转，实现方式为javascript 
$url = "list.php"; 
echo "<script language='javascript' type='text/javascript'>"; 
echo "window.location.href='$url'"; 
echo "</script>"; 
?> 

<?php 
include 'conn.php'; 
$id=$_GET[id]; 
$query="SELECT * FROM message WHERE id =".$id; 
$result=mysql_query($query); 
while ($rs=mysql_fetch_array($result)){ 
?> 
<FORM METHOD="POST" ACTION="postEdit.php"> 
<input type="hidden" name="id" value="<?=$rs[id]?>"> 
用户：<INPUT TYPE="text" NAME="user" value="<?=$rs[user]?>"/><br /> 
标题：<INPUT TYPE="text" NAME="title" value="<?=$rs[title]?>"/><br /> 
内容：<TEXTAREA NAME="content" ROWS="8" COLS="30"><?=$rs[content]?></TEXTAREA><br /> 
<INPUT TYPE="submit" name="submit" value="edit"/> 
</FORM> 
<?php }?> 

<?php 
include 'conn.php'; 
$query="update message set user='$_POST[user]',title='$_POST[title]',content='$_POST[content]' where id='$_POST[id]'"; 
mysql_query($query); 
?> 
<?php 
//页面跳转，实现方式为javascript 
$url = "list.php"; 
echo "<script language='javascript' type='text/javascript'>"; 
echo "window.location.href='$url'"; 
echo "</script>"; 
?>